Vehicles, such as recreational vehicles, are often parked on uneven terrain at campsites, parks, or other similar locations. Consequently, the comfort of the occupants within the vehicle while eating, sleeping, etc., as well as the proper operation of some appliances, such as refrigeration units, may be adversely affected by an out-of-level orientation of the vehicle. Similarly, certain industrial devices may require a level orientation for proper operation and are therefore mounted on platforms that require leveling.
It is known to employ jacks, blocks, or other extendable legs to level a vehicle. Typically, these legs are movable between stowed and use positions. In the stowed position, the vehicle can travel without impedance from the legs. In the use position, the legs can incrementally raise portions of the vehicle in an attempt to level the same. These legs can typically be used on paved or unpaved terrain.
In the case of recreational vehicles which can be parked overnight at certain retail establishments (e.g., Wal-Mart), in contrast to a campground or park, such legs may not always be useful. While retail establishments may allow recreational vehicles to be parked in their parking lot, they may not allow the vehicle to employ its extendable legs for concern of damaging the lot's surface. Accordingly, an alternative leveling apparatus may be required.
The present disclosure is directed to an apparatus and method for automatically leveling a vehicle, such as a recreational vehicle, or platform when the vehicle or platform is stationary and located on uneven terrain or out-of-level surface. One illustrative embodiment includes leveling the vehicle using extendable legs that engage the ground surface. This embodiment can be used in campgrounds and parks. Another illustrative embodiment employs air springs, typically, although not exclusively, those used for suspension of the vehicle, to level the vehicle as well. This embodiment can be used in parking lots or other locations where the use of extendable legs is not permitted.
One illustrative embodiment of the present disclosure provides an apparatus for leveling a vehicle having an air suspension system which comprises an independently adjustable right front suspension assembly, left front suspension assembly, right rear suspension assembly, and left rear suspension assembly, which is mounted to the vehicle. The apparatus for leveling the vehicle comprises a sensor, a controller, and memory. The sensor is mounted to the vehicle to sense pitch and roll of the vehicle relative to a reference level plane. The sensor also produces an orientation signal representing the vehicle pitch and roll. The controller is coupled to the air suspension system and the sensor, wherein the controller, in response to an operator command, levels the vehicle relative to the reference level plane by sequentially actuating the suspension assemblies. The controller interprets the orientation signal to determine an end and a side of the vehicle which are below the reference level plane, then alternating between adjusting the end and the side upwardly by individually, sequentially, or in unison supplying air to the suspension systems at the end and sequentially supplying air to the suspension systems at the side. Each suspension system can be inflated for a first predetermined period of time during each upward adjustment. The controller includes memory for storing data corresponding to the reference level plane, and is configured to write data representing an orientation signal to the memory to replace the reference level plane data with orientation signal data.
The above and other illustrative embodiments may also comprise: a sensor providing an orientation signal to the controller indicating a change in the vehicle orientation when the vehicle is at rest; a controller interpreting an orientation signal after each adjustment to determine whether either an end or side of the vehicle has passed through a reference level plane; upon determining that one end or side of the vehicle has passed through a reference level plane, a controller alternates between adjusting the end or side downwardly by sequentially deflating the suspension assemblies at the one end or side for a second predetermined period of time which is less than the first predetermined period of time, and continuing to adjust the other end or side upwardly by sequentially inflating the suspension assemblies at the other end or side for the first predetermined period of time; a controller that changes the direction of adjustment of an end and side each time they pass through the reference level plane, as indicated by an orientation signal, and reduces the period of time for inflating or deflating suspension assemblies at the end and the side with each passing of the reference level plane; switches for individually actuating the suspension assemblies; a valve assembly for deflating and inflating at least one of the suspension assemblies; a valve assembly provided for each suspension assembly; air that can be selectively added to or exhausted from at least one of the suspension assemblies through the valve assembly; a controller that blocks the ability of at least one suspension assembly from providing suspension to the vehicle when the vehicle is at rest; a controller that initiates the leveling of the vehicle by inflating or deflating at least one of the suspension assemblies after its ability to provide suspension to the vehicle is blocked; and during leveling of the vehicle, air can be added to or subtracted from air already present in the suspension assemblies prior to leveling the vehicle.
Another illustrative embodiment of the present disclosure provides an apparatus for leveling a vehicle having four adjustable air springs mounted to a suspension system on the vehicle at each of the respective corners of the vehicle. Each spring is inflatable and deflatable. A sensor is mounted to the vehicle to sense the pitch and roll of the vehicle, and provide an orientation signal representing the vehicle pitch and roll. A controller is coupled to the springs and the sensor for responding to the vehicle orientation signal by inflating or deflating the springs to adjust the vehicle orientation so it approaches a reference level plane stored as data within the controller.
A method of leveling the vehicle is disclosed which illustratively comprises the steps of: blocking air suspension control to air springs; comparing the orientation signal produced by the sensor; determining a low end and a low side of the vehicle relative to the reference level plane; alternating between sequentially inflating at least one of the air springs at the low end of the vehicle for a first predetermined actuation period, sequentially inflating at least one of the air springs at the low side of the vehicle for a second predetermined actuation period which may be the same as the first predetermined actuation period, determining whether the low end of the vehicle has been moved through the reference level plane after each sequential inflation of the springs at the low end of the vehicle, reversing direction of adjustment of the springs at the low end of the vehicle each time the low end of the vehicle is moved through the reference level plane, reducing the first predetermined actuation period each time the direction of adjustment of the springs at the low end of the vehicle is reversed, determining whether the low side of the vehicle has been moved through the reference level plane after each sequential inflation of the springs at the low side of the vehicle, reversing the direction of adjustment of the springs at the low side of the vehicle each time the low side of the vehicle is moved through the reference level plane, reducing the second predetermined actuation period each time the direction of adjustment of the springs at the low side of the vehicle is reversed, comparing the first and second predetermined actuation period to a preset minimum actuation period and stopping the automatic leveling process when either the first or the second predetermined actuation period is less than the preset minimum actuation period.
The above and other illustrative embodiments may further comprise the steps of: further inflating each air spring until it lifts its respective corner of the vehicle sufficiently that the orientation signal indicates a change in vehicle orientation; stopping the automatic leveling process when the orientation signal represents a vehicle orientation which is within a specified tolerance of the reference level plane.
Another illustrative embodiment of the present disclosure provides an apparatus for automatically leveling a vehicle having four corners. The apparatus comprises adjustable air springs, a level sensor, a controller, and memory. One adjustable air spring is mounted to the vehicle adjacent the left front corner of the vehicle. A second adjustable air spring is mounted to the vehicle adjacent the right front corner of the vehicle. A third adjustable air spring is mounted to the vehicle adjacent the left rear corner of the vehicle. And a fourth adjustable air spring is mounted to the vehicle adjacent the right rear corner of the vehicle. The level sensor is mounted to the vehicle for sensing the pitch and roll orientation of the vehicle relative to horizontal. The level sensor outputs an orientation signal representing the pitch and roll of the vehicle. The controller is connected to the adjustable air springs and the level sensor. The controller also includes a memory for storing data representing a reference level plane and outputs coupled to the adjustable air springs for inflating and deflating the air springs. The controller compares the orientation signal to the reference level plane to determine whether the front or rear of the vehicle is above the reference level plane, and whether the left or right side of the vehicle is below the reference level plane. The controller, being responsive to an operator input to level the vehicle, alternates between sequential adjustments of the air springs at the front or rear of the vehicle which is above the reference level plane, and sequentially deflating at least one of the air springs at the left or right side of the vehicle which is above the reference level plane. The controller actuates each air spring for a first predetermined period of time during each adjustment until the orientation signal indicates that the front, rear, left side, or right side of the vehicle has passed through the reference level plane. Conversely, the controller inflates the air springs corresponding to the front, rear, left side, or right side of the vehicle which has passed through the reference level plane for a second predetermined period of time which is less than the first predetermined period of time.
Another illustrative embodiment of the present disclosure provides an apparatus for automatically leveling a vehicle. The apparatus comprises a plurality of air springs, a sensor, and a controller. The plurality of air springs are each mounted to the vehicle, and each are at least partially inflated to provide suspension to the vehicle. In addition, each of the air springs level the vehicle when the vehicle is parked. The sensor is mounted to the vehicle to sense pitch and roll of the vehicle relative to a reference level plane. The sensor also produces an orientation signal representing the vehicle pitch and roll. The controller is coupled to each of the air springs and the sensor, and monitors the orientation signal received from the sensor. In response to that signal, the controller causes at least one of the air springs to either inflate to move the vehicle upwardly, or deflate to move the vehicle downwardly relative to a ground surface until the orientation of the vehicle reaches the reference level plane within a tolerance.
The above and other illustrative embodiments may also comprise: a plurality of valve assemblies in air communication with the air springs; an air source providing air through the valve assemblies and into the air springs; a controller that blocks the ability of the air springs to provide suspension to the vehicle when the vehicle is at rest; a controller that initiates the leveling of the vehicle by inflating or deflating the air springs after their ability to provide suspension to the vehicle is blocked; and the air springs not being exhausted of air prior to the leveling process.
Additional features and advantages of the leveling apparatus and method will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrated embodiment exemplifying the best mode of carrying out the leveling apparatus and method as presently perceived.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates embodiments of the leveling apparatus and method, and such exemplification is not to be construed as limiting the scope of the leveling apparatus and method in any manner.